Display device

ABSTRACT

According to one embodiment, a display device includes a first substrate including a pixel electrode, a second substrate including a common electrode, a liquid crystal layer located between the first substrate and the second substrate and containing polymer and liquid crystal molecules, and a light emitting element opposed to an end surface of the second substrate, the common electrode being separated from the pixel electrode by a first distance, at a first position, the common electrode being separated from the pixel electrode by a second distance, at a second position more separated from the light emitting element than the first position, the second distance being smaller than the first distance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/474,205, filed Sep. 14, 2021, which is a continuation of PCTApplication No. PCT/JP2019/040307, filed Oct. 11, 2019 and based uponand claiming the benefit of priority from Japanese Patent ApplicationNo. 2019-047367, filed Mar. 14, 2019, the entire contents of all ofwhich are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a display device.

BACKGROUND

A display device that switches a transparent state and a scattered stateusing a polymer dispersed liquid crystal (PDLC) has been proposed. Thisis a technique for switching a transparent state and a scattered stateby partially applying a voltage to PDLC, for the purpose of preventingreflections. The edge light method of arranging a light source at an endportion of a light guide is employed by a transparent display deviceusing PDLC. However, a problem arises that when the edge light method isused in the PDLC display device the luminance is decreased as thedistance from the light source increases.

SUMMARY

The present application generally relates to a display device.

According to one embodiment, a display device includes a first substrateincluding a pixel electrode, a second substrate including a commonelectrode, a liquid crystal layer located between the first substrateand the second substrate and containing polymer and liquid crystalmolecules, and a light emitting element opposed to an end surface of thesecond substrate, the common electrode being separated from the pixelelectrode by a first distance, at a first position, the common electrodebeing separated from the pixel electrode by a second distance, at asecond position more separated from the light emitting element than thefirst position, the second distance being smaller than the firstdistance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing an example of a display device accordingto the embodiments.

FIG. 2 is a cross-sectional view showing a display portion of a displaypanel shown in FIG. 1 .

FIG. 3 is a cross-sectional view schematically showing the displaydevice taken along line A-B shown in FIG. 1 .

FIG. 4 is a cross-sectional view schematically showing the displaydevice taken along line C-D and line E-F shown in FIG. 1 .

FIG. 5 is a diagram showing a relationship among the interelectrodedistance, the field strength, and standardized luminance.

FIG. 6 is a cross-sectional view showing a second configuration exampleof the display device.

FIG. 7 is a cross-sectional view showing a third configuration exampleof the display device.

FIG. 8 is a cross-sectional view showing a fourth configuration exampleof the display device.

FIG. 9 is a cross-sectional view schematically showing the displaydevice taken along line C-D and line E-F shown in FIG. 1 .

FIG. 10 is a cross-sectional view showing a fifth configuration exampleof the display device.

FIG. 11 is a cross-sectional view schematically showing the displaydevice taken along line C-D and line E-F shown in FIG. 1 .

FIG. 12 is a cross-sectional view showing a sixth configuration exampleof the display device.

FIG. 13 is a cross-sectional view schematically showing the displaydevice taken along line G-H shown in FIG. 12 .

DETAILED DESCRIPTION

In general, according to one embodiment, a display device comprises afirst substrate including a pixel electrode, a second substrateincluding a common electrode, a liquid crystal layer located between thefirst substrate and the second substrate and containing polymer andliquid crystal molecules, and a light emitting element opposed to an endsurface of the second substrate, the common electrode being separatedfrom the pixel electrode by a first distance, at a first position, thecommon electrode being separated from the pixel electrode by a seconddistance, at a second position more separated from the light emittingelement than the first position, the second distance being smaller thanthe first distance.

According to another embodiment, a display device comprises a firstsubstrate including a first electrode, a second substrate having asecond electrode, a first end surface, and a second end surface on anopposite side to the first end surface, a liquid crystal layer locatedbetween the first substrate and the second substrate, and a lightemitting element opposed to the first end surface, the second substratehaving a first position and a second position located between the firstposition and the second end surface, a distance between the firstelectrode and the second electrode at the first position being largerthan a distance between the first electrode and the second electrode atthe second position.

According to another embodiment, a display device comprises a firstsubstrate, a second substrate having a first end surface and a secondend surface on an opposite side to the first end surface, a liquidcrystal layer sealed between the first substrate and the secondsubstrate by a seal, and a light emitting element opposed to a seallocated on the first end surface side, in a direction from the first endsurface to the second end surface, a thickness of a seal located on thefirst end surface side being larger than a thickness of a seal locatedon the second end surface.

Embodiments will be described hereinafter with reference to theaccompanying drawings. The disclosure is merely an example, and properchanges in keeping with the spirit of the invention, which are easilyconceivable by a person of ordinary skill in the art, come within thescope of the invention as a matter of course. In addition, in somecases, in order to make the description clearer, the widths,thicknesses, shapes and the like, of the respective parts areillustrated schematically in the drawings, rather than as an accuraterepresentation of what is implemented. However, such schematicillustration is merely exemplary, and in no way restricts theinterpretation of the invention. In addition, in the specification anddrawings, structural elements which function in the same or a similarmanner to those described in connection with preceding drawings aredenoted by like reference numbers, detailed description thereof beingomitted unless necessary.

First Configuration Example

FIG. 1 is a plan view showing an example of a display device DSPaccording to the embodiments.

For example, the first direction X, the second direction Y, and thethird direction Z are orthogonal to each other but may intersect at anangle other than 90 degrees. The first direction X and the seconddirection Y correspond to the directions parallel to the surface of asubstrate which constitutes the display device DSP, and the thirddirection Z corresponds to the thickness direction of the display deviceDSP. In the present specification, a direction from a first substrateSUB1 to a second substrate SUB2 is referred to as an upward direction(or, more simply, upwardly) and a direction from the second substrateSUB2 to the first substrate SUB1 is referred to as a downward direction(or, more simply, downwardly). According to “a second member on/above afirst member” and “a second member under/below a first member”, thesecond member may be in contact with the first member or may beseparated from the first member. An observation position at which thedisplay device DSP is observed is assumed to be located on the tip sideof the arrow indicating the third direction Z, and viewing from theobservation position toward the X-Y plane defined by the first directionX and the second direction Y is called a planar view.

In the embodiments, a liquid crystal display device employing polymerdispersed liquid crystal will be described as an example of the displaydevice DSP. The display device DSP comprises a display panel PNL, awiring board 1, an IC chip 2, and a light emitting element LD.

The display panel PNL comprises a first substrate SUB1, a secondsubstrate SUB2, a liquid crystal layer LC, and a seal SL. The firstsubstrate SUB1 and the second substrate SUB2 are formed in a flat plateparallel to the X-Y plane. The first substrate SUB1 and the secondsubstrate SUB2 are overlaid in planar view. The first substrate SUB1 andthe second substrate SUB2 are bonded to each other by the seal SL. Theliquid crystal layer LC is held between the first substrate SUB1 and thesecond substrate SUB2, and is sealed by the seal SL. In FIG. 1 , theliquid crystal layer LC and the seal SL are represented by differenthatch lines.

As schematically enlarged in FIG. 1 , the liquid crystal layer LCcomprises polymer dispersed liquid crystal containing polymer 31 andliquid crystal molecules 32. For example, the polymer 31 is liquidcrystal polymer. The polymer 31 is formed in a stripe shape extending inone direction. For example, an extending direction DR1 of the polymer 31is a direction parallel to the first direction X. The liquid crystalmolecules 32 are dispersed in gaps of the polymer 31 and aligned suchthat their major axes extend in the first direction X. The polymer 31and the liquid crystal molecules 32 have optical anisotropy orrefractive anisotropy. The response performance of the polymer 31 to theelectric field is lower than the response performance of the liquidcrystal molecules 32 to the electric field.

For example, the orientation of alignment of the polymer 31 is hardlyvaried irrespective of the presence or absence of the electric field. Incontrast, the orientation of alignment of the liquid crystal molecules32 is varied in accordance with the electric field in a state in which avoltage higher than or equal to a threshold value is applied to theliquid crystal layer LC. In a state in which the voltage is not appliedto the liquid crystal layer LC, optical axes of the polymer 31 and theliquid crystal molecules 32 are parallel to one another and the lightmade incident on the liquid crystal layer LC is transmitted withoutbeing substantially scattered in the liquid crystal layer LC(transparent state). In a state in which the voltage is applied to theliquid crystal layer LC, optical axes of the polymer 31 and the liquidcrystal molecules 32 intersect one another and the light made incidenton the liquid crystal layer LC is scattered in the liquid crystal layerLC (scattered state).

The display panel PNL comprises a display portion DA on which an imageis displayed and a non-display portion NDA in a bezel shape surroundingthe display portion DA. The seal SL is located at the non-displayportion NDA. The display portion DA comprises pixels PX arrayed in amatrix in the first direction X and the second direction Y.

As enlarged in FIG. 1 , each pixel PX comprises a switching element SW,a pixel electrode (first electrode) PE, a common electrode (commonelectrode) CE, a liquid crystal layer LC and the like. The switchingelement SW is composed of, for example, a thin-film transistor (TFT) andis electrically connected to a scanning line G and a signal line S. Thescanning line G is electrically connected to the switching element SW ineach of the pixels PX arranged in the first direction X. The signal lineS is electrically connected to the switching element SW in each of thepixels PX arranged in the second direction Y. The pixel electrode PE iselectrically connected to the switching element SW. Each pixel electrodePE is opposed to the common electrode CE in the third direction Z, anddrives the liquid crystal layer LC (particularly, liquid crystalmolecules 32) by an electric field which is produced between the pixelelectrode PE and the common electrode CE. A capacitor CS is formed, forexample, between an electrode of the same electric potential as thecommon electrode CE and an electrode of the same potential as the pixelelectrode PE. The first substrate SUB1 includes a plurality of pixelelectrodes PE. The second substrate SUB2 includes at least one commonelectrode CE.

The wiring board 1 is electrically connected to an extended portion Exof the first substrate SUB1. The wiring board 1 is a foldable flexibleprinted circuit board. The IC chip 2 is electrically connected to thewiring board 1. The IC chip 2 incorporates, for example, a displaydriver which outputs a signal necessary for image display, and the like.The IC chip 2 may be electrically connected to the extended portion

Ex. The wiring board 1 and the IC chip 2 often read signals from thedisplay panel PNL but mainly function as signal sources which supplysignals to the display panel PNL.

The light emitting element LD is overlaid on the extended portion Ex. Aplurality of light emitting elements LD are spaced apart and arranged inthe first direction X. These light emitting elements LD are opposed toan end surface (first end surface) E21 of the second substrate SUB2 andemit light toward the end surface E21. The second substrate SUB2 has anend surface (second end surface) E22 on the side opposed to the endsurface E21, and the light emitted from the light emitting elements LDreaches the end surface E22.

FIG. 2 is a cross-sectional view showing the display portion DA of thedisplay panel PNL shown in FIG. 1 . The liquid crystal layer LC isprovided between the first substrate SUB1 and the second substrate SUB2.

The first substrate SUB1 comprises a transparent substrate (secondtransparent substrate) 10, an organic insulating film (second organicinsulating film) 11, a capacitive insulating film 12, a capacitiveelectrode 13, the switching element SW, and a pixel electrode PE, and analignment film AL1.

The transparent substrate 10 comprises a main surface 10A and a mainsurface 10B on a side opposite to the main surface 10A. The switchingelement SW is arranged on the main surface 10B side. The switchingelement SW may be a bottom-gate type switching element having a gateelectrode located under the semiconductor layer or may be a top-gatetype switching element having a gate electrode located on thesemiconductor layer. The semiconductor layer is formed of, for example,amorphous silicon, but may be formed of polycrystalline silicon or anoxide semiconductor.

The organic insulating film 11 covers the switching element SW. Inaddition, the organic insulating film 11 is located between thetransparent substrate 10 and the pixel electrode PE. The scanning line Gand the signal line S shown in FIG. 1 are arranged between thetransparent substrate 10 and the organic insulating film 11, but theirillustration is omitted. The scanning line G, the signal line Sintersecting the scanning line G, the switching element SW electricallyconnected to the scanning line G and the signal line S, and the organicinsulating film 11 overlaid on the switching element SW are located onthe transparent substrate 10. The capacitive electrode 13 is arrangedbetween the organic insulating film 11 and the capacitive insulatingfilm 12. The pixel electrode PE is arranged for each pixel PX betweenthe capacitive insulating film 12 and the alignment film AL1. The pixelelectrode PE is electrically connected to the switching element SWthrough an opening portion OP of the capacitive electrode 13. The pixelelectrode PE is overlaid on the capacitive electrode 13 through thecapacitive insulating film 12 to form the capacitor CS of the pixel PX.The alignment film AL1 covers the pixel electrode PE. The alignment filmAL1 is in contact with the liquid crystal layer LC.

The second substrate SUB2 comprises a transparent substrate (firsttransparent substrate) 20, a common electrode CE, an organic insulatingfilm (first organic insulating film) 21, and an alignment film AL2. Thetransparent substrate 20 has a main surface 20A and a main surface 20Bon a side opposite to the main surface 20A. The main surface 20A of thetransparent substrate 20 is opposed to the main surface 10B of thetransparent substrate 10. The organic insulating film 21 is provided onthe main surface 20A and is located between the transparent substrate 20and the common electrode CE. The common electrode CE is provided betweenthe liquid crystal layer LC and the organic insulating film 21. Thecommon electrode CE is arranged over the plurality of pixels PX and isopposed to the plurality of pixel electrodes PE in the third directionZ. The alignment film AL2 covers the common electrode CE. In addition,the alignment film AL2 is in contact with the liquid crystal layer LC.The second substrate SUB2 may comprise a light shielding layerimmediately above the scanning line G, the signal line S, and theswitching element SW.

The transparent substrates 10 and 20 are insulating substrates such asglass substrates or plastic substrates. The organic insulating films 11and 21 are formed of a transparent insulating material such as acrylicresin. The capacitive insulating film 12 is an inorganic insulating filmof silicon nitride or the like. The capacitive electrode 13, the pixelelectrodes PE, and the common electrode CE are transparent electrodesformed of a transparent conductive material such as indium tin oxide(ITO) or indium zinc oxide (IZO). For example, the alignment films AL1and AL2 are subjected to alignment treatment in the first direction X.The alignment treatment may be a rubbing treatment or an opticalalignment treatment.

FIG. 3 is a cross-sectional view schematically showing the displaydevice DSP on line A-B shown in FIG. 1 . Only main constituent elementsof the present invention are shown, and the illustration of the othermembers is omitted.

A cover member CM is located on the transparent substrate 20. The lightemitting element LD is opposed to the cover member CM, the transparentsubstrate 20, the liquid crystal layer LC, and the seal SL in the seconddirection Y. The light emitting element LD is opposed to the seal SLlocated on the end surface E21 side in the direction from the endsurface E21 to the end surface E22. In addition, the light emittingelement LD is electrically connected to a wiring board F. A light guidemay be interposed between the light emitting element LD and thetransparent substrate 20. The scattered state of the light incident onthe liquid crystal layer LC from the light emitting element LD ischanged by the voltage applied between the pixel electrode PE and thecommon electrode CE.

The first position P1 close to the light emitting element LD and thesecond position P2 separated from the light emitting element LD from thefirst position P1 are defined here. The second substrate SUB2 has thefirst position P1 and the second position P2. The second position P2 islocated between the first position P1 and the end surface E22. Theorganic insulating film 21 has a thickness T1 at the first position P1and a thickness T2 at the second position P2. The thickness T1 issmaller than the thickness T2. The thickness of the organic insulatingfilm 21 increases as the distance from the light emitting element LDincreases. That is, the thickness of the organic insulating film 21gradually increases from the first position P1 to the second positionP2. For this reason, a surface 211 of the organic insulating film 21 onthe first substrate SUB1 side is slanted to the transparent substrate20. Thus, an interelectrode distance D between the common electrode CEand the pixel electrode PE becomes smaller as the distance from thelight emitting element LD increases, due to the shape of the organicinsulating film 21. At the first position P1, the common electrode CE isseparated from the pixel electrode PE by a first distance D1. At thesecond position P2, the common electrode CE is separated from the pixelelectrode PE by a second distance D2. The second distance D2 is smallerthan the first distance D1. In other words, the first distance D1between the pixel electrode PE and the common electrode CE at the firstposition P1 is larger than the second distance D2 between the pixelelectrode PE and the common electrode CE at the second position P2. Thatis, the distance between the pixel electrode PE and the common electrodeCE gradually decreases from the first position P1 to the second positionP2. In addition, a thickness SLT1 of the seal SL located on the endsurface E21 side is larger than a thickness SLT2 of the seal SL locatedon the end surface E22 side. A thickness LCT of the liquid crystal layerLC gradually decreases from the end surface E21 to the end surface E22.

In the display device DSP to which the polymer dispersed liquid crystalis applied, the light emitting element LD is located to be opposed tothe end surface E21 of the second substrate SUB2. For this reason, thelight emitted from the light emitting element LD is absorbed by lines, alight shielding layer, an organic insulating film, or the like, or isused for scattering such that the light is reduced as the distance fromthe light emitting element LD is increased. That is, the luminance ofthe display device DSP may decrease from an incident side to ananti-incident side. The incident side corresponds to the side on whichthe light emitting element LD is located, i.e., the end surface E21side, and the anti-incident side corresponds to the side opposed to theend surface E21, i.e., the end surface E22 side.

According to the embodiments, the interelectrode distance D between thecommon electrode CE and the pixel electrode PE decreases as the distancefrom the light emitting element LD increases, such that the electricfield strength between the common electrode CE and the pixel electrodePE increases as the distance from the light emitting element LDincreases. For this reason, the decrease in luminance from the incidentside to the anti-incident side can be suppressed. The degradation indisplay quality of the display device DSP can be thereby suppressed.

FIG. 4 is a cross-sectional view schematically showing the displaydevice DSP on lines C-D and E-F shown in FIG. 1 . FIG. 4(a) is across-sectional view on line C-D. A position of line C-D is assumed tobe a first position P1 shown in FIG. 3 . FIG. 4(b) is a cross-sectionalview on line E-F. A position of line E-F is assumed to be a secondposition P2 shown in FIG. 3 .

As shown in FIG. 4(a), the organic insulating film 21 has a uniformthickness T1 at the first position P1. In addition, the first distanceD1 is uniform at the first position P1. The display device DSP has afirst spacer SP1 at the first position P1. The first spacer SP1 has aheight H1. Such a spacer form a predetermined cell gap between the firstsubstrate SUB1 and the second substrate SUB2 and is, for example,arranged for each pixel PX. As shown in FIG. 4(b), the organicinsulating film 21 has a uniform thickness T2 at the second position P2.In addition, the second distance D2 is uniform at the second positionP2. In the embodiments, the thickness of the organic insulating film 21and the interelectrode distance D are uniform in a directionperpendicular to the direction from the incident side to theanti-incident side. In other words, the thickness of the organicinsulating film 21 and the interelectrode distance D change depending onthe position, in the Y-Z section of the display device DSP shown in FIG.1 , but the thickness of the organic insulating film 21 and theinterelectrode distance D are constant in the X-Z section. The displaydevice DSP has a second spacer SP2 at the second position P2. The secondspacer SP2 has a height H2. The height H1 of the first spacer SP1 islarger than the height H2 of the second spacer SP2. That is, the heightof the spacer decreases from the incident side to the anti-incidentside, similarly to the interelectrode distance.

In the embodiments, the interelectrode distance is adjusted inaccordance with the shape of the organic insulating film 21, but may beadjusted in accordance with the height of the spacer. In this case, thethickness of the organic insulating film 21 may or may not be uniformfrom the incident side to the anti-incident side. In addition, theorganic insulating film for adjusting the interelectrode distance may beformed on not the second substrate SUB2, but the first substrate SUB1,which will be described later. Alternatively, organic insulating filmsmay be formed on both the first substrate SUB1 and the second substrateSUB2. The degree of reducing the interelectrode distance from theincident side to the anti-incident side can be arbitrarily changedaccording to the application.

FIG. 5 is a diagram showing a relationship among the interelectrodedistance, the field strength, and standardized luminance.

FIG. 5(a) shows a case where the interelectrode distance D is uniformfrom the incident side to the anti-incident side. That is, the firstdistance D1 is equal to the second distance D2. For example, the uniforminterelectrode distance D is approximately 3 μm. At this time, the ratiobetween the luminance L1 at the first position P1 and the luminance L2at the second position P2 is 5:2. The luminance L2 of the secondposition P2 is reduced by 60% with respect to the luminance L1 of thefirst position P1. In order for the luminance to be visually recognizeduniformly, the first distance D1 and the second distance D2 may be setsuch that the luminance L1 and L2 is 2:5 when it is assumed that theluminance does not decrease.

FIG. 5(b) is a graph showing the relationship between the field strengthand the standardized luminance.

The lateral axis of the graph indicates the field strength [MV/m], andthe longitudinal axis of the graph indicates the standardized luminance.The field strength is assumed to be V0 in a case where theinterelectrode distance D shown in FIG. 5(a) is 3 μm. When theinterelectrode distance D is smaller than 3 μm, the field strengthbecomes larger than the field strength V0 and the standardized luminancealso increases. In addition, when the interelectrode distance D islarger than 3 μm, the field strength becomes smaller than the fieldstrength V0 and the standardized luminance also decreases. In thisexample, the field strength V1 smaller than the field strength V0 is setto be applied to the first position P1, and the field strength V2 largerthan the field strength V0 is set to be applied to the second positionP2. If it is assumed that the luminance does not decrease from theincident side to the anti-incident side, the standardized luminance L11is obtained at the first position P1 when the field strength is V1, andthe standardized luminance L12 is obtained at the second position P2when the field intensity is V2. The ratio between the standardizedluminance L11 and L12 becomes a numerical value close to 2:5.

FIG. 5(c) shows a case where the interelectrode distance D decreasesfrom the incident side to the anti-incident side. At the first positionP1, the interelectrode distance D is set to the first distance D1 wherethe field strength V1 can be obtained. In addition, at the secondposition P2, the interelectrode distance D is set to the second distanceD2 where the field strength V2 can be obtained. At this time, forexample, the first distance D1 is larger than 3 μm, and the seconddistance D2 is smaller than 3 μm. For example, the first distance D1 isabout 4.4 μm and the second distance D2 is about 2.5 μm. Even when auniform voltage is applied, the field strength increases from theincident side to the anti-incident side and the visually recognizedluminance can be made uniform by adjusting the interelectrode distancein this manner.

Second Configuration Example

FIG. 6 is a cross-sectional view showing a second configuration exampleof the display device DSP. The display device DSP shown in FIG. 6 has adifferent shape of the organic insulating film 21 as compared with thedisplay device DSP shown in FIG. 3 .

The thickness of the organic insulating film 21 gradually increases fromthe incident side to the anti-incident side. The organic insulating film21 has a thickness T11 in the first region AR1, a thickness T12 in thesecond region AR2, a thickness T13 in the third region AR3, and athickness T14 in the fourth region AR4. The thickness T12 is larger thanT11, the thickness T13 is larger than the thickness T12, and thethickness T14 is larger than the thickness T13. That is, the surface 211is formed in a stepped shape. Due to the shape of the organic insulatingfilm 21, the interelectrode distance D gradually decreases from theincident side to the anti-incident side. The display device DSP has aninterelectrode distance D11 in the first region AR1, an interelectrodedistance D12 in the second region AR2, an interelectrode distance D13 inthe third region AR3, and an interelectrode distance D14 in the fourthregion AR4. The interelectrode distance D12 is smaller than theinterelectrode distance D11, the interelectrode distance D13 is smallerthan the interelectrode distance D12, and the interelectrode distanceD14 is smaller than the interelectrode distance D13. In the exampleillustrated, the organic insulating film 21 has the thickness in 4steps, but may have the thickness in 3 steps or less or 5 steps or more.

In the second configuration example, too, the same advantages as thoseof the first configuration example can be obtained.

Third Configuration Example

FIG. 7 is a cross-sectional view showing a third configuration exampleof the display device DSP. The display device DSP shown in FIG. 7 has adifferent shape of the organic insulating film 21 as compared with thedisplay device DSP shown in FIG. 3 .

A surface 211 of the organic insulating film 21 is curved and recessedtoward the transparent substrate 20 side.

In the third configuration example, too, the same advantages as those ofthe first configuration example can be obtained.

Fourth Configuration Example

FIG. 8 is a cross-sectional view showing a fourth configuration exampleof the display device DSP. The display device DSP shown in FIG. 8 isdifferent from the display device DSP shown in FIG. 3 in that theinterelectrode distance is adjusted by not the organic insulating filmof the second substrate SUB2, but the organic insulating film 11 of thefirst substrate SUB1.

The organic insulating film 11 has a thickness T21 at the first positionP1 and a thickness T22 at the second position P2. The thickness T21 issmaller than the thickness T22. The thickness of the organic insulatingfilm 11 increases as the distance from the light emitting element LDincreases. For this reason, the surface 111 of the organic insulatingfilm 11 on the second substrate SUB2 side is slanted to the transparentsubstrate 10. Due to such a shape of the organic insulating film 11, theinterelectrode distance D becomes smaller as the distance from the lightemitting element LD increases. The second distance D2 is smaller thanthe first distance D1.

As shown in FIG. 3 and FIG. 8 , at least one of the first substrate SUB1and the second substrate SUB2 includes an organic insulating film, andthe thickness at the first position P1 of the organic insulating film issmaller than the thickness at the second position P2 of the organicinsulating film.

FIG. 9 is a cross-sectional view schematically showing the displaydevice DSP on lines C-D and E-F shown in FIG. 1 . FIG. 9(a) is across-sectional view on line C-D. A position of line C-D is assumed tobe a first position P1 shown in FIG. 8 . FIG. 9(b) is a cross-sectionalview on line E-F. A position of line E-F is assumed to be a secondposition P2 shown in FIG. 8 .

As shown in FIG. 9(a), the organic insulating film 11 has a uniformthickness T21 at the first position P1. In addition, the first distanceD1 is uniform at the first position P1. The first spacer SP1 has aheight H11. As shown in FIG. 9(b), the organic insulating film 11 has auniform thickness T22 at the second position P2. In addition, the seconddistance D2 is uniform at the second position P2. The second spacer SP2has a height H12. The height H11 of the first spacer SP1 is larger thanthe height H12 of the second spacer SP2. The height of the spacerdecreases from the incident side to the anti-incident side, similarly tothe interelectrode distance.

In the fourth configuration example, too, the same advantages as thoseof the first configuration example can be obtained. The shape of theorganic insulating film 11 of the fourth configuration example may beformed to be a stepped shape as shown in FIG. 6 , or a recessed shape asshown in FIG. 7 .

Fifth Configuration Example

FIG. 10 is a cross-sectional view showing a fifth configuration exampleof the display device DSP. The display device DSP shown in FIG. 10 isdifferent from the display device DSP shown in FIG. 3 in that theinterelectrode distance by both the organic insulating film 21 of thesecond substrate SUB2 and the organic insulating film 11 of the firstsubstrate SUB1.

The organic insulating film 11 has a thickness T31 at the first positionP1 and a thickness T32 at the second position P2. The thickness T31 issmaller than the thickness T32. The thickness of the organic insulatingfilm 11 increases as the distance from the light emitting element LDincreases. For this reason, the surface 111 of the organic insulatingfilm 11 on the second substrate SUB2 side is slanted to the transparentsubstrate 10. The organic insulating film 21 has a thickness T41 at thefirst position P1 and a thickness T42 at the second position P2. Thethickness T41 is smaller than the thickness T42. The thickness of theorganic insulating film 21 increases as the distance from the lightemitting element LD increases. For this reason, a surface 211 of theorganic insulating film 21 on the first substrate SUB1 side is slantedto the transparent substrate 20. Due to such shapes of the organicinsulating films 11 and 21, the interelectrode distance D becomessmaller as the distance from the light emitting element LD increases.The second distance D2 is smaller than the first distance D1.

FIG. 11 is a cross-sectional view schematically showing the displaydevice DSP on lines C-D and E-F shown in FIG. 1 . FIG. 11(a) is across-sectional view on line C-D. A position of line C-D is assumed tobe a first position P1 shown in FIG. 10 . FIG. 11(b) is across-sectional view on line E-F. A position of line E-F is assumed tobe a second position P2 shown in FIG. 10 .

As shown in FIG. 11(a), the organic insulating film 11 has a uniformthickness T31, and the organic insulating film 21 has a uniformthickness T41, at the first position P1. In addition, the first distanceD1 is uniform at the first position P1. The first spacer SP1 has aheight H21. As shown in FIG. 11(b), the organic insulating film 11 has auniform thickness T32, and the organic insulating film 21 has a uniformthickness T42, at the second position P2. In addition, the seconddistance D2 is uniform at the second position P2. The second spacer SP2has a height H22. The height H21 of the first spacer SP1 is larger thanthe height H22 of the second spacer SP2. The height of the spacerdecreases from the incident side to the anti-incident side, similarly tothe interelectrode distance.

In the fifth configuration example, too, the same advantages as those ofthe first configuration example can be obtained. The shapes of theorganic insulating films 11 and 21 of the fifth configuration examplemay be formed to be the stepped shape as shown in FIG. 6 or the recessedshape as shown in FIG. 7 .

Sixth Configuration Example

FIG. 12 is a cross-sectional view showing a sixth configuration exampleof the display device DSP. The sixth configuration example is differentfrom the first configuration example in that the organic insulating film11 of the first substrate SUB1 is arranged at a position overlaid on thescanning line G, the signal line S, and the switching element SW, but isnot arranged at a position overlaid on the pixel electrode PE.

FIG. 12 shows the configuration of the first substrate SUB1 of the pixelPX. The first substrate SUB1 comprises scanning lines G, signal lines Sintersecting the scanning lines G, the switching element SW electricallyconnected to the scanning lines G and the signal lines S, a metal lineM, the organic insulating film 11, the capacitive electrode 13, thepixel electrode PE and the like.

Two scanning lines G extend in the first direction X to be arranged inthe second direction Y with an interval. Two signal lines S extend inthe second direction Y to be arranged in the first direction X with aninterval. The pixel PX corresponds to a region partitioned by two signallines S and two scanning lines G. The switching element SW is arrangedat an intersection of the gate line G and the source line S.

The organic insulating film 11 is patterned and formed in a gratingshape in planar view. That is, the organic insulating film 11 isoverlaid on each of the gate lines G, the source lines S, and theswitching element SW. The organic insulating film 11 includes firstparts 11X overlaid on the scanning lines G and second parts 11Y overlaidon the signal lines S. The first part 11X has a first side surface E1close to the light emitting element LD and a second side surface E2 onthe opposite side of the first side surface E1. The first side surfaceE1 and the second side surface E2 extend along the extension directionDR1 of the polymer 31. The second part 11Y has a third side surface E3and a fourth side surface E4 on the opposite side of the third sidesurface E3.

In FIG. 12 , a region in which the organic insulating film 11 isarranged is referred to as a first region A1 of the first substrateSUB1, and a region in which the organic insulating film 11 is notarranged is referred to as a second region A2 of the first substrateSUB1. The second region A2 is located on an inner side surrounded by thefirst region A1.

The metal line M is arranged in the first region A1 and formed in agrating shape in planar view. That is, the metal line ML is overlaid oneach of the scanning line G, the signal line S, and the switchingelement SW. The metal line M includes a first wiring part MX overlaid onthe scanning line G and the first part 11X, and a second wiring part MYoverlaid on the signal line S and the second part 11Y.

The capacitive electrode 13 is arranged over a plurality of pixels PX asrepresented by a one-dot chain line, and further arranged over asubstantially entire area of the first substrate SUB1. That is, thecapacitance electrode 13 is arranged in each of the first region A1 andthe second region A2. The capacitive electrode 13 is overlaid on each ofthe switching element SW, the scanning line G, the signal line S, andthe organic insulating film 11 in the first region A1.

The pixel electrode PE is overlaid on the capacitance electrode 13 inthe second region A2. In the example shown in FIG. 12 , the pixelelectrode PE is provided inside the region where the organic insulatingfilm 11 is arranged. The pixel electrode PE may be provided to beoverlaid on each of the first part 11X and the second part 11Y. In theexample shown in FIG. 12 , the spacer SP is overlaid on the switchingelement SW.

FIG. 13 is a cross-sectional view schematically showing the displaydevice DSP on line G-H shown in FIG. 12 . In addition to theconfiguration shown in FIG. 2 , FIG. 13 illustrates the signal lines S,the insulating films 8 and 9, and the metal lines M on the firstsubstrate SUB1, and illustrates the light-shielding layer BM on thesecond substrate SUB2.

The insulating film 8 covers the transparent substrate 10. The otherconductive layer (light-shielding layer or reflective layer) formed ofthe same material as the scanning line G may be provided between theinsulating film 8 and the transparent substrate 10. The signal line Sare formed on the insulating layer 11. The signal line S is locatedbetween the pixel electrodes PE adjacent in the first direction X. Theinsulating film 9 covers the signal lines S and the insulating film 8.

The organic insulating film 11 is located on the insulating film 9. Thesecond part 11Y of the organic insulating film 11 is located directlyabove the signal line S and is located between the pixel electrodes PEadjacent in the first direction X. The third side surface E3 and thefourth side surface E4 of the second part 11Y are covered with thecapacitance electrode 13. Each of the third side surface E3 and thefourth side surface E4 is located between the signal line S and thepixel electrode PE along the first direction X. In the sixthconfiguration example, the organic insulating film 11 is not providedbetween the transparent substrate 10 and the pixel electrode PE. Forthis reason, the total volume of the organic insulating film 11 issmaller than that in the case where the organic insulating film 11 isprovided between the transparent substrate 10 and the pixel electrode PE(or the entire area of the display portion DA). As a result, since theprobability that the light propagating through the display panel PNL ismade incident on the organic insulating film 11 is reduced, the lightabsorption by the organic insulating film 11 can be suppressed.Deterioration in display quality can be therefore suppressed. The secondwiring parts MY of the metal lines M are located on the organicinsulating film 11. The second wiring parts MY are located directlyabove the signal lines S. In addition, the second wiring parts MY are incontact with the capacitance electrode 13 and are electrically connectedto each other. The second part 11Y is located between the signal line Sand the second wiring part MY.

In the second substrate SUB2, the light-shielding layer BM is locatedbetween the transparent substrate 20 and the organic insulating film 21.The light-shielding layer BM is located directly above the third sidesurface E3 and the fourth side surface E4 of the second part 11Y, anddirectly above the signal line S. In the sixth configuration example,the organic insulating film 21 may have a configuration described in thefirst to third configuration examples.

In the sixth configuration example, too, the same advantages as those ofthe first configuration example can be obtained.

As described above, a display device capable of suppressing thedeterioration in display quality can be provided by the embodiments.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

Examples of the display device obtained from the configurationsdisclosed herein will be added below.

(1)

A display device comprising:

-   -   a first substrate including a pixel electrode;    -   a second substrate including a common electrode;    -   a liquid crystal layer located between the first substrate and        the second substrate and containing polymer and liquid crystal        molecules; and    -   a light emitting element opposed to an end surface of the second        substrate, wherein    -   the common electrode is separated from the pixel electrode by a        first distance, at a first position,    -   the common electrode is separated from the pixel electrode by a        second distance, at a second position more separated from the        light emitting element than the first position, and    -   the second distance is smaller than the first distance.

(2)

The display device of (1), wherein

-   -   the second substrate includes a first base substrate, and a        first organic insulating film located between the first base        substrate and the common electrode, and    -   a thickness of the first organic insulating film at the first        position is smaller than a thickness of the first organic        insulating film at the second position.

(3)

The display device of (2), wherein

-   -   the thickness of the first organic insulating film gradually        increases from the first position to the second position.

(4)

The display device of (2), wherein

-   -   a surface of the first organic insulating film on the first        substrate side has a stepped shape.

(5)

The display device of (2), wherein

-   -   a surface of the first organic insulating film on the first        substrate side is curved.

(6)

The display device of (1), further comprising:

-   -   a first spacer at the first position and a second spacer at the        second position,    -   wherein    -   a height of the first spacer is larger than a height of the        second spacer.

(7)

The display device of (1), wherein

-   -   the first substrate includes a second base substrate, and a        second organic insulating film located between the second base        substrate and the pixel electrode, and    -   a thickness of the second organic insulating film at the first        position is smaller than a thickness of the second organic        insulating film at the second position.

(8)

The display device of (7), wherein

-   -   the second substrate includes a first base substrate, and a        first organic insulating film located between the first base        substrate and the common electrode, and    -   a thickness of the first organic insulating film at the first        position is smaller than a thickness of the first organic        insulating film at the second position.

(9)

The display device of (1), wherein

-   -   the first substrate includes a second base substrate, and        comprises a scanning line, a signal line intersecting the        scanning line, a switching element electrically connected to the        scanning line and the signal line, and a second organic        insulating film overlaid on the switching element, on the second        base substrate, and    -   the second organic insulating film is not provided between the        second base substrate and the pixel electrode.

(10)

The display device of (9), wherein

-   -   the second organic insulating film is overlaid on the scanning        line and the signal line.

(11)

The display device of (1), wherein

-   -   the first distance is longer than 3 μm and the second distance        is smaller than 3 μm.

(12)

A display device comprising:

-   -   a first substrate including a first electrode;    -   a second substrate having a second electrode, a first end        surface, and a second end surface on an opposite side to the        first end surface;    -   a liquid crystal layer located between the first substrate and        the second substrate; and    -   a light emitting element opposed to the first end surface,        wherein    -   the second substrate has a first position and a second position        located between the first position and the second end surface,        and    -   a distance between the first electrode and the second electrode        at the first position is larger than a distance between the        first electrode and the second electrode at the second position.

(13)

The display device of (12), wherein

-   -   the distance between the first electrode and the second        electrode gradually decreases from the first position to the        second position.

(14)

The display device of (12), wherein

-   -   the first substrate includes a second base substrate, and a        second organic insulating film located between the second base        substrate and the first electrode,    -   a thickness of the second organic insulating film at the first        position is smaller than a thickness of the second organic        insulating film at the second position,    -   the second substrate includes a first base substrate, and a        first organic insulating film located between the first base        substrate and the second electrode, and    -   a thickness of the first organic insulating film at the first        position is smaller than a thickness of the first organic        insulating film at the second position.

(15)

The display device of (12), wherein

-   -   the liquid crystal layer is sealed between the first substrate        and the second substrate by a seal, and    -   the light emitting element is opposed to the seal.

(16)

A display device comprising:

-   -   a first substrate;    -   a second substrate having a first end surface and a second end        surface on an opposite side to the first end surface;    -   a liquid crystal layer sealed between the first substrate and        the second substrate by a seal; and    -   a light emitting element opposed to a seal located on the first        end surface side, in a direction from the first end surface to        the second end surface, wherein    -   a thickness of a seal located on the first end surface side is        larger than a thickness of a seal located on the second end        surface.

(17)

The display device of (16), wherein

-   -   the light emitting element is opposed to the first end surface.

(18)

The display device of (16), wherein

-   -   a thickness of the liquid crystal layer gradually decreases from        the first end surface to the second end surface.

(19)

The display device of (16), wherein

-   -   the first substrate includes a first electrode, a second base        substrate, and a second organic insulating film located between        the second base substrate and the first electrode,    -   a thickness of the second organic insulating film at a first        position is smaller than a thickness of the second organic        insulating film at a second position,    -   the second substrate includes a second electrode, a first base        substrate, and a first organic insulating film located between        the first base substrate and the second electrode, and    -   a thickness of the first organic insulating film at the first        position is smaller than a thickness of the first organic        insulating film at the second position.

(20)

The display device of (16), wherein

-   -   the first substrate includes a plurality of first electrodes,    -   the second substrate includes at least one second electrode,    -   the liquid crystal layer contains polymer dispersed liquid        crystal, and    -   a scattered state of light incident on the liquid crystal layer        from the light emitting element is changed by a voltage applied        between the first electrode and the second electrode.

What is claimed is:
 1. A display device comprising: a first substrateincluding a first base substrate including a first main surface, and apixel electrode disposed on the first main surface; a second substrateopposed to the first substrate and including a second base substrateincluding a second main surface which is opposed to the first mainsurface, and a common electrode disposed on the second main surface, thesecond substrate including a first side surface, and a second sidesurface which is on an opposite side to the first side surface; a liquidcrystal layer located between the first main surface and the second mainsurface and containing polymer and liquid crystal molecules; and a lightemitting element opposed to the first side surface, wherein the commonelectrode has a first end part and a second end part on an opposite sideto the first end part, the first end part being closer to the first sidesurface than the second end part, the pixel electrode has a third endpart and a fourth end part on an opposite side to the third end part,the third end part being closer to the first side surface than thefourth end part, the first end part and the third end part oppose eachother at a first position, the second end part and the fourth end partoppose each other at a second position, a distance between the first endpart and the third end part is greater than a distance between thesecond end part and the fourth end part, the first side surface and thesecond side surface intersect the second main surface, and the secondmain surface is a flat surface from the first side surface to the secondside surface.
 2. The display device of claim 1, wherein the secondsubstrate includes a first organic insulating film located between thesecond base substrate and the common electrode, and a thickness of thefirst organic insulating film at the first position is smaller than athickness of the first organic insulating film at the second position.3. The display device of claim 2, wherein the thickness of the firstorganic insulating film gradually increases from the first position tothe second position.
 4. The display device of claim 2, wherein a surfaceof the first organic insulating film on the first substrate side has astepped shape between the first position and the second position.
 5. Thedisplay device of claim 2, wherein a surface of the first organicinsulating film on the first substrate side is curved.
 6. The displaydevice of claim 1, further comprising: a first spacer at the firstposition and a second spacer at the second position, wherein a height ofthe first spacer is larger than a height of the second spacer.
 7. Thedisplay device of claim 1, wherein the first substrate includes a secondorganic insulating film located between the first base substrate and thepixel electrode, and a thickness of the second organic insulating filmat the first position is smaller than a thickness of the second organicinsulating film at the second position.
 8. The display device of claim7, wherein the second substrate includes a first organic insulating filmlocated between the second base substrate and the common electrode, anda thickness of the first organic insulating film at the first positionis smaller than a thickness of the first organic insulating film at thesecond position.
 9. The display device of claim 1, wherein the firstsubstrate includes a scanning line, a signal line intersecting thescanning line, a switching element electrically connected to thescanning line and the signal line, and a second organic insulating filmoverlaid on the switching element, on the first base substrate, and thesecond organic insulating film is not provided between the first basesubstrate and the pixel electrode.
 10. The display device of claim 9,wherein the second organic insulating film is overlaid on the scanningline and the signal line.
 11. The display device of claim 1, wherein thedistance between the first end part and the third end part is longerthan 3 μm and the distance between the second end part and the fourthend part is smaller than 3 μm.